| Noun | 1. | fathom - a linear unit of measurement (equal to 6 feet) for water depthyard, pace - a unit of length equal to 3 feet; defined as 91.44 centimeters; originally taken to be the average length of a stride | |
| 2. | fathom - (mining) a unit of volume (equal to 6 cubic feet) used in measuring bodies of ore | |
| Verb | 1. | fathom - come to understandunderstand - know and comprehend the nature or meaning of; "She did not understand her husband"; "I understand what she means" | |
| 2. | fathom - measure the depth of (a body of water) with a sounding linemeasure, quantify - express as a number or measure or quantity; "Can you quantify your results?" | |